The present invention relates generally to elevator drives and, in particular, to a direct drive apparatus for an elevator car.
A linear motor arrangement for an elevator is shown in the European patent document EP 0 846 646, in which a movable part of a linear motor is arranged near a counterweight and is connected with the counterweight by way of a horizontal, non-conductive connection. The movable part of the linear motor is thereby horizontally movable with the counterweight, so that horizontal forces are not transmitted between the motor and the counterweight. The counterweight is guided at a guide rail and the movable part is guided on an adjacent plane. A resilient connecting element between the counterweight and the movable part serves the purpose of avoiding excess allowances which can arise due to the different guidances of the movable part and the counterweight.
In this known solution the oscillations and vibrations arising in the direction of travel are not damped by the described construction of the connecting element.
The present invention concerns a direct drive arrangement that has the advantage, compared with the state of the art drives, that the oscillations and vibrations arising in the direction of travel are significantly reduced and damped. Advantageously, no disturbing vibrations in the car body are caused by the drive.
A further advantage of the present invention is that the damping properties of the tension/compression strut can be set coarsely and finely. The tension/compression strut is advantageously provided with material transitions in order to undertake not only an oscillation damping function, but also a body sound insulating function.
Of further advantage is the spring behavior of the tension/compression strut independent of direction. This is the same in both directions of loading.
An advantage is further to be seen in that not only the car, but also the counterweight can be used as the driven body of the elevator.
All explained features are usable not only in the respectively indicated combination, but also in other combinations or in isolation with departing from the scope of the present invention.